Golf is the most popular sport for wealthy people. Ever watch (and not fall asleep) a golfing event on TV? Advertisements are for ridiculous luxury goods and asset management services.
And Woods alone attracts a not-inconsiderable portion of the audience: TV ratings for this year's US PGA Championship were around 50% higher than for the same tournament last year, the principal difference being Woods' absence in 2008 due to injury.
Online social networking has an extremely low value-per-impression.
Professional golfing has an extremely high value-per-impression.
Which explains why Tiger Woods has generated more in profits than the entire history of the online social networking business.